1. Field of the Invention
The present invention relates broadly to tourmaline. A first and second aspect of the invention relate to a method of depositing an ionic material using tourmaline crystals to removing metals from a liquid such as water.
A third and fourth aspect of the invention relate to a tourmaline crystal with a deposited metal thereon for supplying metallic ions to a liquid such as water.
A fifth aspect of the present invention relates to catalysts in general and to metal catalysts carried on carriers in particular. More specifically, this aspect of the invention is directed to a metal catalyst carried or deposited on a carrier comprising a fine powder of tourmaline crystals and a method for producing such a metal catalyst.
1. Description of the Related Art
The applicant for the present invention has filed an application on Oct. 3, 1989 (Japanese Patent Application No. 57130/1989) for a patent on an invention, the title of which is "Interfacial Purifying Apparatus Using Tourmaline, Method thereof, and Tourmaline Granular Material". This invention relates to a method, apparatus and application thereof, utilizing a discovery of the inventor that an interfacial active function can be provided for a liquid such as water by the reaction of electrodes, that is, between the permanent electrodes contained in tourmaline and liquid molecules of water, etc., to produce a purified liquid, such as water or the like.
Traditionally, where metallic ions have been contained in water, there have been requirements for removing the heavy metal ions which are harmful to life and the metallic ions, such as iron, manganese, etc., which produce adverse effects when the water is used. There have been proposed various kinds of methods and apparatus for this purpose. The fundamental technique, however, is that solid particles of metallic oxide and other compounds are produced in a solution using oxygen, chlorine, ozone, etc., and that these particles are separated for removal by means of sedimentation and filtration.
With respect to the methods and apparatus for removing the metallic ions themselves, there have been known a method and apparatus using zeolite and a method using ion exchange resin. These methods and apparatus, however, have a disadvantage that the reduced adsorptivity and the deteriorated ion exchange resin cause considerable problems. Therefore, an aeration process using oxygen in the air is a more widely employed method.
Even with the aeration method, there are many instances in practice that before the oxidation has been completed, the treatment proceeds to the next step where the separation is performed and that the solid particles produced by the oxidation are too fine to be sufficiently separated.
There are many reasons why these problems have been caused, but the principal reason is that the speeds of the oxidizing reaction and the resulting aggregation are not fast, requiring a certain period of time for the oxidation to complete its reaction. This slow reaction has been the greatest barrier for the prior art to overcome.
In respect to the first, second and third aspects of the invention, the methods and apparatus described above constitute their prior art. The prior art regarding the fourth aspect of the invention will subsequently be described.
As one of the typical examples of this prior art, there are a method and apparatus for dispersing an aqueous solution of copper sulfate to remove algae that has grown in a pond, lake, pool, cooling tower etc. by its eradication. It is known that algae become almost eradicated by copper ion of extremely low concentration such as 5 ppb (1/1,000 of ppm). However, the dispersion of copper sulfate is not suited for uniformally producing such an extremely low concentration as this. It is difficult to dissolve copper ions widely in a large quantity of water only by dispersion. There is locally produced a high concentration of copper sulfate where sulfate ion becomes as concentrated as copper ion. This sulfate ion is harmful to life such as fish or people swimming in the pool. The supply of copper ions to water cannot be sustained, either. Of metallic salts, a water-soluble salt is employed (irrespective of whether it is easy to be dissolved of not), but only a metallic ion is needed for the eradication of algae and the object an ion which is produced simultaneously should be a harmless one.
The prior art regarding the fifth aspect of the invention will subsequently be described.
Catalysts have been used in the chemical industry since the beginning of the 19th century. The discovery of catalysts is tantamount to the birth of the chemical industry. The discovery of new catalysts has especially influenced the development of the petrochemical industry since its origin in about 1960.
A variety of catalysts have been well-known in the art. Among them, there are metal catalysts, most of which are obtained by vapor-depositing catalytic metal components on the surfaces of powders of metal oxides such as alumina (Al.sub.2 O.sub.3). These catalysts are called "catalysts-on-carriers." Practically, they are pelletized for use.
A catalyst is essentially a substance having the following properties:
1) It increases the rates of chemical reactions. PA1 2) It undergoes in itself no permanent change before and after reactions. PA1 3) It produces an effect in minute amounts. PA1 4) It has no action on thermodynamically unfeasible reactions. PA1 5) It does not alter the equilibrium points of reversible reactions, but accelerates the reactions in the forward and reverse directions.
The catalyst substance may be present in various phases, typically, gas, liquid and solid phases. Reactions whose products are in phase with catalysts are referred to as homogeneous catalytic reactions, and reactions whose products are out of phase with catalysts are referred to as heterogeneous catalytic reactions.
The catalysts, which are referred to in the present disclosure, are present in a solid state, including metal, metal oxide and solid acid (e.g., SiO.sub.2, Al.sub.2 O.sub.3 or zeolite) catalysts. In particular, this invention is directed to the type of metal catalysts-on-carriers most commonly used as catalysts. When present in wire or planar forms, the metals are so limited in surface area that they cannot efficiently serve as catalysts. Fine metal powders are often awkward to handle, and are sintered at high temperature (200.degree. C. or higher), resulting in surface area reductions.
To solve these problems, metal catalysts-on-carriers are presently produced by dispersing and depositing catalytic metal components throughout and on thermally and chemically stable metal oxides. As is well-known in the art, even the same metal catalyst may vary in terms of its surface properties depending on the properties of the carrier or how it is made, i.e. the so-called "carrier effect".
For instance, alumina (Al.sub.2 O.sub.3) and/or silica (SiO.sub.2) and/or magnesia (MgO.sub.2) are used as carriers. This is because these substances are solid acid substances and so have the carrier effect. Besides, NiO, ZnO and other semiconductor metal oxides as well as metal sulfides such as WS.sub.2 are used as catalysts. Presently available catalysts are generally classified as shown in Table 1.
TABLE 1 __________________________________________________________________________ Typical Types Examples Examples of Reactions __________________________________________________________________________ Metal Fe,Ni,Pd Pt,Ag,Co, W,Re, Ge,Ir, ##STR1## ##STR2## Seconductor Oxides NiO,ZnO, MnO.sub.2,TiO.sub.2 Cr.sub.2 O.sub.3, ##STR3## and Sulfides Bi.sub.2 O.sub.3, .MoO.sub.3 WS.sub.2 NisMoS Cos, ##STR4## Insu- lators AL.sub.2 O.sub.3 SiO.sub.2,MgO ##STR5## Acids H.sub.3 PO.sub.4 SiO.sub.2Al.sub.2 O.sub.3 (Cyrstal- line, Amorphous) Al.sub.2 O.sub.3 SiO.sub.2 zeolite ##STR6## Catalysts are available in an electrode form as well, to which electrical
Petrochemical plants, the use of various fuels produced there, and automobiles spew pollutant gases inclusive of car exhaust gas into the atmosphere, giving rise to a variety of pollution problems on a global scale such as photochemical smog and acid rain. In addition, a serious problem is arising in connection with petroleum resources. In order to solve these energy- and resource-related problems, there is thus an urgent demand for developing highly active and selective catalysts.
Since many metals serving as catalysts are expensive, there is a cost-effective problem as well.
Catalysts formed by electrodes themselves, on the other hand, are not catalysts in the true sense of the word, because electric energy has to be externally supplied thereto or, in other words, the overall mechanisms of the electrode reactions involve energy consumption.